(03-31-2014, 08:28 PM)space45 Wrote: raised my PS level from 4 to 6, may raise it some more to say 7, want to get my min o2 levels to 88% if possible
also raised my max IPAP back up to 25 and the min EPAP to 10
my CA was only 0.5 max CA was 15 seconds, most were 10.
I suggest holding off on further adjustments for a week.
Raising the PS will increase the average SpO2, but probably will not increase the minimum SpO2 during deep dips, and it is important not to set PS too high.
Since your central events are short, your deep dips in SpO2 may be from obstructve apneas, during which PS probably completely stops. Because PS is synchronized to your breathing, if you stop breathing, PS also stops. I suggest using ResScan or SleepyHead to look at the Flow waveform and the High Rate Pressure waveform to see what is happening during the deep dips in SpO2.
It is primarily the EPAP pressure which needs to be high enough to prevent obstructive apneas and the deep desaturations. Your machine will automatically raise the EPAP pressure when needed.
Often, staying off one's back while asleep is very important for avoiding obstructive events.
The PS should not be so high that your SpO2 stays higher than about 94% to 96%. When O2 is too high it can cause too much oxidation in the blood, too many free radicals, can render prescription medications ineffective and lead to ill health. This is definitely a case of "too much of a good thing can kill you."
Too much PS can also increase centrals, but if your CAI is 0.5/hr and all your central events are short, that does not seem to be an issue in your case.